Phascolarctos cinereus, the koala, is a member of the Diprodontia. This taxon encompasses a large range of sizes and shapes and includes wombats, possums, wallabies, and kangaroos. These seemingly diverse animals posses a number of characters that unite them together, such as diprotodont dentition (the two midlle incisors of the lower jaw are greatly enlarged and project forward), syndactyly (the second and third digits fo the hindfoot are joined by skin), fewer than three upper incisors, and selenodont dentition.

The koala is found only in Australia from southeastern Queensland to eastern New South Whales and Victoria to southeastern South Australia. Their fossil record extends back to the mid-Miocene, and they seem to have occupied a more extended range. The koala primarily is noctural and spends most of its time in eucalyptus trees. Its diet consists largely of eucalyptus leaves, but it may also eat mistletoe or box leaves. Until the early twentieth century, the koala was ubiquitous in southeastern Australia. Hunting and habitat destruction, however, seems to be the primary contributors to its decline. The IUCN currently lists the koala as near threatened.

About the Species

This specimen (TMM M-2946), exchanged from Monash University, Australia, is the skull of Phascolarctos cinereus. It was made available to the University of Texas High-Resolution X-ray CT Facility for scanning by Dr. Timothy Rowe of The University of Texas at Austin. Funding for image processing was provided by a National Science Foundation Digital Libraries Initiative grant to Dr. Rowe.

About this Specimen

The specimen was scanned by Matthew Colbert on 22 August 2003 along the coronal axis for a total of 599 slices, each slice 0.238 mm thick with an interslice spacing of 0.238 mm.